Wax Worm Caterpillars Have a Taste for Plastic

Federica Bertocchini’s discovery that wax worms can eat through plastic happened completely by accident. Bertocchini, an amateur beekeeper, was dismayed to find that her beehives were infested by wax worm caterpillars. After cleaning out the hive, she went to pick up the plastic bags she had placed the pests in, only to find the bags riddled with holes.

“I removed the worms, and put them in a plastic bag while I cleaned the panels,”Bertocchini said in a press release about the research.” After finishing, I went back to the room where I had left the worms and I found that they were everywhere. They had escaped from the bag even though it had been closed and when I checked, I saw that the bag was full of holes. There was only one explanation: the worms had made the holes and had escaped. This project began there and then.”

Bertocchini also happens to be a scientist who works at the Institute of Biomedicine and Biotechnology of Cantabria in Spain. She was curious to find out whether the wax worms were just chewing on the plastic, or were able to digest it as well. Bertocchini and her colleagues decided to test this idea by making a pulp out of the wax worms and spreading it onto a sheet of polyethylene plastic. The result? The plastic degraded without any mechanical action (such as chewing). The scientists also found that, not only was the plastic broken down, but it was also transformed into ethylene glycol, a compound commonly used in antifreeze.

Wax worms get their name by their habit of living in beehives. Mature worms lay their eggs in the hives, and after the eggs hatch, the larvae feed on the beeswax. Beeswax is made up of a very diverse mixture of lipid compounds. According to the researchers, biodegrading wax and polyethylene both involve breaking strong carbon bonds.

How or where this process occurs in wax worms is not yet understood. In fact, there could be a middleman of sorts, such as a bacteria in the worm’s gut that initiates the process. Even with their apparent taste for plastic bags, given the wax worm’s pest status, dumping a huge pile of them on plastic trash wouldn’t be an ideal solution. Instead, the researchers hope to use this new-found knowledge to develop a biotechnological solution to the ever-growing problem of plastic waste.

“We are planning to implement this finding into a viable way to get rid of plastic waste, working towards a solution to save our oceans, rivers, and all the environment from the unavoidable consequences of plastic accumulation,” Bertocchini said in the press release. “However, we should not feel justified to dump polyethylene deliberately in our environment just because we now know how to biodegrade it.”